RT Journal Article
SR Electronic
T1 Characterizing alterations in the pulmonary surfactant system in a rat model of Pseudomonas aeruginosa pneumonia
JF European Respiratory Journal
JO Eur Respir J
FD European Respiratory Society
SP 1388
OP 1396
DO 10.1183/09031936.98.12061388
VO 12
IS 6
A1 J Vanderzwan
A1 L McCaig
A1 S Mehta
A1 M Joseph
A1 J Whitsett
A1 DG McCormack
A1 JF Lewis
YR 1998
UL http://erj.ersjournals.com/content/12/6/1388.abstract
AB Bacterial pneumonia remains a significant cause of patient morbidity and mortality worldwide. Pulmonary surfactant serves to maintain homeostasis in the lung through the maintenance of alveolar stability and the regulation of the alveolar immune response. The purpose of this study was to characterize the lung injury and associated surfactant alterations in a rat model of acute Pseudomonas aeruginosa pneumonia. Pneumonia was induced in male Sprague-Dawley rats via intratracheal injection of 0.2 ml, phosphate-buffered saline (PBS) containing P. aeruginosa (6x10(8) colony-forming units x mL(-1)). Control animals received 0.2 mL sterile PBS. Twenty-four hours after inoculation, the pneumonia group (PN) exhibited clinical signs of pneumonia including deficits in gas exchange, leukopenia and elevated arterial lactate levels. Morphological assessment confirmed the presence of pneumonia with airspaces filled with polymorphonuclear cells. Lung homogenate analysis demonstrated evidence of bacterial colonization of pneumonic lung tissue. Lung compliance was also significantly lower in the PN group. Lung lavage analysis of PN rats revealed the pooled surfactant levels to be lower and the surfactant function reduced compared to control rats. Surfactant composition was also found to be altered in PN rats. These results demonstrate that in Pseudomonas aeruginosa pneumonia, the pulmonary surfactant system is both poorly functioning and reduced in quantity. These alterations may contribute to the lung dysfunction characteristic of this disorder.